The invention relates to a plant-protection mat, particularly in the form of a perforated disk,
Known plant-protection mats (DE 2537056) in the form of perforated disks, are provided as soil coverage above the root bale of plantations. The covering mats are constructed as two-layer parts with a felt layer, having jute and coconut fibers, and an additional fabric layer. These two-layer parts have to be combined by quilting or needle-punching, so that the manufacturing expense is disadvantageously increased. In addition, the different materials of the covering mats cause a disadvantageously high expense during the disposal.
The invention is concerned with the problem of creating a plant-protection mat, particularly in the form of a perforated disk, which can be produced with little expenditure for material and costs in largely any size and has a structure, stable for a sufficiently long period of time, so that it can be used repeatedly as a water-storing as well as an opaque protective element and disposed of easily.
The inventive plant-protection mat is constructed as a molded object, which consists only of coconut fibers and latex and the coconut fibers of which, fixed at a contour-forming reinforcing edge, in conjunction with the latex particles of the nonwoven coconut fiber material, form light-tight and at least regionally liquid-storing covering zones with pore structures improving the usefulness of the mat. Moreover, the molded object can be handled well, remains dimensionally stable even under rough use conditions and, while having adequate decaying resistance, enables repeated as well as long-term stable use of the perforated disks with largely any dimensions and circumferential contours. The disposal of such plant-protection mats is extremely easy, since their latex components and coconut fiber components can decay completely and, with that, the mats can be comminuted at little cost and composted.
The nonwoven coconut fiber material, intended for the production of the plant-protection mat, advantageously may consist of unsorted, processed coconut fibers, which are loosened over a porcupine roller or the like from a crude bale, removed and supplied to a conveyor belt under the action of gravity, so that in each case shorter coconut fiber portions form a lower zone and longer coconut fibers an upper zone of the nonwoven sheet intended as an intermediate product. The nonwoven sheet is sprayed with a binder (latex), so that a disordered combination of nonwoven parts is formed in the cross section of the sheet. In an appropriate embodiment, the parts by weight of coconut fiber and latex mixture supplied are equal, that is, in each case 50% by weight of coconut fiber and 50% by weight of latex mixture are supplied for forming the nonwoven.
Subsequently, in a continuous passage with a short residence time, this nonwoven sheet is supplied to a severing process, carried out by means of a punching tool, several perforated disks being severed simultaneously from the nonwoven sheet in a single punching action. During this severing process, the contour-forming reinforcing edge is formed, in the region of which the coconut fibers and the latex components, which have not cured up to this time, are consolidated under the action of the cutting force in such a manner, that subsequently the stiffened edges impart an advantageous contour stability to the perforated disks. At the same time, the pore structures, forming different opening widths, are formed in the top and bottom of the covering zone by a consolidation of the coconut fiber-latex combination. The perforated disks, punched out of the nonwoven sheet, can be compressed to about 30% of the initial height of the nonwoven coconut fiber sheet.
In an appropriate construction, the perforated disk can also be produced from two layers of nonwoven coconut fibers, connected in the region of the stiffening edges. In this case, the layer of nonwoven coconut fibers, which is the lower one in the use position, is already prepared as a consolidated nonwoven sheet by a pressing process taking place before the punching process. This layer then forms the lower covering zone with comparatively small opening width. The second sheet-shaped nonwoven coconut fiber layer, consisting of loosely connected coconut fibers and latex, is placed over this nonwoven coconut layer. After that, the joint severing and punching process takes place, so that a perforated disk with a stable contour and two covering zones is achieved.
For the above-described production of the perforated disks, the severing process also forms the radial slit starting out from the central hole. The contour of the disk, the central hole and the radial slit are produced in one operation by the punching equipment, so that the manufacturing expense is very low.